scholarly journals Enhanced terahertz detection of multigate graphene nanostructures

Nanophotonics ◽  
2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Juan A. Delgado-Notario ◽  
Wojciech Knap ◽  
Vito Clericò ◽  
Juan Salvador-Sánchez ◽  
Jaime Calvo-Gallego ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Thz Radiation ◽  
Electron Hole ◽  
Back Gate ◽  
Potential Barriers ◽  
Terahertz Detection ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Effect Transistor

Abstract Terahertz (THz) waves have revealed a great potential for use in various fields and for a wide range of challenging applications. High-performance detectors are, however, vital for exploitation of THz technology. Graphene plasmonic THz detectors have proven to be promising optoelectronic devices, but improving their performance is still necessary. In this work, an asymmetric-dual-grating-gate graphene-terahertz-field-effect-transistor with a graphite back-gate was fabricated and characterized under illumination of 0.3 THz radiation in the temperature range from 4.5 K up to the room temperature. The device was fabricated as a sub-THz detector using a heterostructure of h-BN/Graphene/h-BN/Graphite to make a transistor with a double asymmetric-grating-top-gate and a continuous graphite back-gate. By biasing the metallic top-gates and the graphite back-gate, abrupt n+n (or p+p) or np (or pn) junctions with different potential barriers are formed along the graphene layer leading to enhancement of the THz rectified signal by about an order of magnitude. The plasmonic rectification for graphene containing np junctions is interpreted as due to the plasmonic electron-hole ratchet mechanism, whereas, for graphene with n+n junctions, rectification is attributed to the differential plasmonic drag effect. This work shows a new way of responsivity enhancement and paves the way towards new record performances of graphene THz nano-photodetectors.

scholarly journals Plasmonic semiconductor nanogroove array enhanced broad spectral band millimetre and terahertz wave detection

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jinchao Tong ◽  
Fei Suo ◽  
Tianning Zhang ◽  
Zhiming Huang ◽  
Junhao Chu ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
High Performance ◽  
Room Temperature ◽  
Spectral Band ◽  
High Capacity ◽  
Terahertz Wave ◽  
Semiconductor Surface ◽  
Wide Range ◽  
Low Sensitivity ◽  
Air Interfaces

AbstractHigh-performance uncooled millimetre and terahertz wave detectors are required as a building block for a wide range of applications. The state-of-the-art technologies, however, are plagued by low sensitivity, narrow spectral bandwidth, and complicated architecture. Here, we report semiconductor surface plasmon enhanced high-performance broadband millimetre and terahertz wave detectors which are based on nanogroove InSb array epitaxially grown on GaAs substrate for room temperature operation. By making a nanogroove array in the grown InSb layer, strong millimetre and terahertz wave surface plasmon polaritons can be generated at the InSb–air interfaces, which results in significant improvement in detecting performance. A noise equivalent power (NEP) of 2.2 × 10−14 W Hz−1/2 or a detectivity (D*) of 2.7 × 1012 cm Hz1/2 W−1 at 1.75 mm (0.171 THz) is achieved at room temperature. By lowering the temperature to the thermoelectric cooling available 200 K, the corresponding NEP and D* of the nanogroove device can be improved to 3.8 × 10−15 W Hz−1/2 and 1.6 × 1013 cm Hz1/2 W−1, respectively. In addition, such a single device can perform broad spectral band detection from 0.9 mm (0.330 THz) to 9.4 mm (0.032 THz). Fast responses of 3.5 µs and 780 ns are achieved at room temperature and 200 K, respectively. Such high-performance millimetre and terahertz wave photodetectors are useful for wide applications such as high capacity communications, walk-through security, biological diagnosis, spectroscopy, and remote sensing. In addition, the integration of plasmonic semiconductor nanostructures paves a way for realizing high performance and multifunctional long-wavelength optoelectrical devices.

scholarly journals Silicon Field Effect Transistor as the Nonlinear Detector for Terahertz Autocorellators

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3735 ◽  
Author(s):  
Kęstutis Ikamas ◽  
Ignas Nevinskas ◽  
Arūnas Krotkus ◽  
Alvydas Lisauskas
Keyword(s):  
Threshold Voltage ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Cryogenic Cooling ◽  
Thz Radiation ◽  
Gate Bias ◽  
Large Signal ◽  
Wide Range ◽  
Effect Transistor ◽  
Thz Power

We demonstrate that the rectifying field effect transistor, biased to the subthreshold regime, in a large signal regime exhibits a super-linear response to the incident terahertz (THz) power. This phenomenon can be exploited in a variety of experiments which exploit a nonlinear response, such as nonlinear autocorrelation measurements, for direct assessment of intrinsic response time using a pump-probe configuration or for indirect calibration of the oscillating voltage amplitude, which is delivered to the device. For these purposes, we employ a broadband bow-tie antenna coupled Si CMOS field-effect-transistor-based THz detector (TeraFET) in a nonlinear autocorrelation experiment performed with picoseconds-scale pulsed THz radiation. We have found that, in a wide range of gate bias (above the threshold voltage V th = 445 mV), the detected signal follows linearly to the emitted THz power. For gate bias below the threshold voltage (at 350 mV and below), the detected signal increases in a super-linear manner. A combination of these response regimes allows for performing nonlinear autocorrelation measurements with a single device and avoiding cryogenic cooling.

A Self-powered and Sensitive Terahertz Photodetection based on PdSe2

2022 ◽  
Author(s):  
Jie Zhou ◽  
Xueyan Wang ◽  
Zhiqingzi Chen ◽  
Libo Zhang ◽  
Chengyu Yao ◽  
...  
Keyword(s):  
Homeland Security ◽  
Room Temperature ◽  
Performance Enhancement ◽  
Rapid Development ◽  
Rapid Response ◽  
Medical Sciences ◽  
Terahertz Detection ◽  
Order Of Magnitude ◽  
Self Powered ◽  
Low Dimensional

Abstract With the rapid development of terahertz technology, terahertz detectors are expected to play a key role in diverse areas such as homeland security and imaging, materials diagnostics, biology and medical sciences, communication. Whereas self-powered, rapid response, and room temperature terahertz photodetectors are confronted with huge challenges. Here, we report a novel rapid response and self-powered terahertz photothermoelectronic (PTE) photodetector based on a low-dimensional material: palladium selenide (PdSe2). An order of magnitude performance enhancement was observed in photodetection based on PdSe2/graphene heterojunction that resulted from the integration of graphene and enhanced the Seebeck effect. Under 0.1 THz and 0.3 THz irradiation, the device displays a stable and repeatable photoresponse at room temperature without bias. Furthermore, rapid rise (5.0 μs) and decay (5.4 μs) times are recorded under 0.1 THz irradiation. Our results demonstrate the promising prospect of the detector based on PdSe2 in terms of air-stable, suitable sensitivity, and speed, which may have great application in terahertz detection.

scholarly journals SLOW5: a new file format enables massive acceleration of nanopore sequencing data analysis

2021 ◽  
Author(s):  
Hasindu Gamaarachchi ◽  
Hiruna Samarakoon ◽  
Sasha P. Jenner ◽  
James M Ferguson ◽  
Timothy G. Amos ◽  
...  
Keyword(s):  
Data Analysis ◽  
High Performance ◽  
Nanopore Sequencing ◽  
File Format ◽  
Sequencing Data ◽  
Genome Wide ◽  
Wide Range ◽  
File Structure ◽  
Order Of Magnitude ◽  
Methylation Profiling

Nanopore sequencing is an emerging genomic technology with great potential. However, the storage and analysis of nanopore sequencing data have become major bottlenecks preventing more widespread adoption in research and clinical genomics. Here, we elucidate an inherent limitation in the file format used to store raw nanopore data, known as FAST5, that prevents efficient analysis on high-performance computing (HPC) systems. To overcome this we have developed SLOW5, an alternative file format that permits efficient parallelisation and, thereby, acceleration of nanopore data analysis. For example, we show that using SLOW5 format, instead of FAST5, reduces the time and cost of genome-wide DNA methylation profiling by an order of magnitude on common HPC systems, and delivers consistent improvements on a wide range of different architectures. With a simple, accessible file structure and a ~25% reduction in size compared to FAST5, SLOW5 format will deliver substantial benefits to all areas of the nanopore community.

A MoS2 Field-Effect Transistor With a Liquid Back Gate

2016 ◽  
Author(s):  
Kabin Lin ◽  
Zhishan Yuan ◽  
Yu Yu ◽  
Kun Li ◽  
Haojie Yang ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Gate Voltage ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistor ◽  
Control Effect ◽  
Back Gate ◽  
Potential Applications ◽  
Source Current ◽  
Effect Transistor

The two-dimensional layer of Molybdenum disulfide (MoS2) has attracted much interest due to its direct-gap property and potential applications in the field of catalysis, nanotribology, microelectronics, lithium batteries, hydrogen storage, medical, high-performance flexible electronics and optoelectronics. In this paper, based on few-layer MoS2 acquired by mechanical exfoliation method, a MoS2 liquid-gated field effect transistor (L-FET) is fabricated. Simultaneously, the few-layer MoS2 is characterized by Raman spectral. Then, the performance of MoS2-based L-FET devices is investigated by a source meter instrument in the different back gate voltage of 0.1mol/L NaCl solution. The result reveals that the Schottky barriers is formed between platinum and few-layer MoS2 and the back gate voltage has a great control effect with the drain-to-source current of MoS2 field effect transistor.

scholarly journals Performance Evaluation of GAA Nanosheet FET with Varied Geometrical and Process Parameters

2021 ◽  
Author(s):  
Aruna Kumari Neelam ◽  
Prithvi P
Keyword(s):  
Temperature Compensation ◽  
High Performance ◽  
Field Effect Transistor ◽  
Performance Metrics ◽  
Electrical Characteristics ◽  
Transfer Characteristics ◽  
Wide Range ◽  
Effect Transistor ◽  
20 Nm ◽  
The Impact

Abstract Nanosheet Field Effect Transistor (NSFET) is a viable contender for future scaling in sub-7-nm technology. This paper provides insights into the variations of DC FOMs for different geometrical configurations of the NSFET. In this script, DC performance of 3D GAA NSFET is analyzed by varying the width, thickness of the device. Moreover, the gate length is scaled from 20 nm to 5 nm to check for the device suitability in logic applications. The thickness and width of each nanosheet are varied in the range of 5 to 9 nm, and 10 to 50 nm respectively to analyse the performance dependency on the geometry of the device. The impact of geometry of NSFET on various DC performance metrics like transfer characteristics, sub-threshold swing (SS), on current (ION), off current (IOFF), switching ratio (ION/IOFF), threshold voltage (Vth) and drain induced barrier lowering (DIBL) are studied. On top of that, the device’s electrical characteristics are analyzed for a wide range of temperatures from -43oC to 127oC to identify the temperature compensation point and is observed at VGS = 0.55 V and ID = 3.86 × 10−6 A. Furthermore, the important process parameter, work function variations on transfer characteristics of the device is analyzed. Moreover, the analyses tell that, for sub -7 nm, the NSFET is a potential device for high performance and good logic applications.

scholarly journals Design and Investigation of the High Performance Doping-Less TFET with Ge/Si0.6Ge0.4/Si Heterojunction

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 424 ◽  
Author(s):  
Tao Han ◽  
Hongxia Liu ◽  
Shupeng Chen ◽  
Shulong Wang ◽  
Wei Li
Keyword(s):  
Integrated Circuits ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistor ◽  
Structure Parameters ◽  
Device Structure ◽  
Ultra Low Power ◽  
Order Of Magnitude ◽  
Effect Transistor ◽  
Channel Control

A high performance doping-less tunneling field effect transistor with Ge/Si0.6Ge0.4/Si heterojunction (H-DLTFET) is proposed in this paper. Compared to the conventional doping-less tunneling field effect transistor (DLTFET), the source and channel regions of H-DLTFET respectively use the germanium and Si0.6Ge0.4 materials to get the steeper energy band, which can also increase the electric field of source/channel tunneling junction. Meanwhile, the double-gate process is used to improve the gate-to-channel control. In addition, the effects of Ge content, electrode work functions, and device structure parameters on the performance of H-DLTFET are researched in detail, and then the above optimal device structure parameters can be obtained. Compared to the DLTFET, the simulation results show that the maximum on-state current, trans-conductance, and output current of H-DLTFET are all increased by one order of magnitude, whereas the off-state current is reduced by two orders of magnitude, so the switching ratio increase by three orders of magnitude. At the same time, the cut-off frequency and gain bandwidth product of H-DLTFET increase from 1.75 GHz and 0.23 GHz to 23.6 GHz and 4.69 GHz, respectively. Therefore, the H-DLTFET is more suitable for the ultra-low power integrated circuits.

Development of High Surface Area Titania on Glass Fibre Supports for Photocatalysis

2014 ◽  
Vol 93 ◽  
pp. 196-202
Author(s):  
Pelin Yilmaz ◽  
Armando Marsden Lacerda ◽  
Igor Larrosa ◽  
Steve Dunn
Keyword(s):  
Visible Light ◽  
Surface Area ◽  
Glass Fibre ◽  
High Performance ◽  
Direct Injection ◽  
High Surface ◽  
Hydrothermal Process ◽  
High Surface Area ◽  
Electron Hole ◽  
Order Of Magnitude

We show that we have developed a hydrothermal process that produces a high surface area TiO2on glass fibre supports. The as produced titania shows good photocatalytic activity against a standard commercial dye – Rhodamine B– giving full decolourisation within 3 hours under UV and visible light irradiation. The samples are mechanically robust and can act as a photocatalytic filter for waste streams and pollutants. In addition to testing the standard titania we also photochemically deposit nanostructures of Pd. These hybrid catalysts show enhanced decolourisation by an order of magnitude over the native titania systems. This enhanced performance is due to the increased energy harvesting of the hybrid system through a visible light plasmon interaction and the direct injection of electrons from the noble metal into the adsorbed dye molecules. There is a clear relationship between the absorbed light and photochemical reactivity of the system which is further explained in terms of electron hole generation and separation and plasmonic interaction. In summary, we have generated a high performance catalyst that is produced on a bulk commodity substrate with enhanced activity due to control of the surface plasmon and direct band gap transition of electron hole pairs in the semi-conductor.

scholarly journals SLOW5: a new file format enables massive acceleration of nanopore sequencing data analysis

2021 ◽  
Author(s):  
Hasindu Gamaarachchi ◽  
Hiruna Samarakoon ◽  
Sasha Jenner ◽  
James Ferguson ◽  
Timothy Amos ◽  
...  
Keyword(s):  
Data Analysis ◽  
High Performance ◽  
Nanopore Sequencing ◽  
File Format ◽  
Sequencing Data ◽  
Genome Wide ◽  
Wide Range ◽  
File Structure ◽  
Order Of Magnitude ◽  
Methylation Profiling

Abstract Nanopore sequencing is an emerging genomic technology with great potential. However, the storage and analysis of nanopore sequencing data have become major bottlenecks preventing more widespread adoption in research and clinical genomics. Here, we elucidate an inherent limitation in the file format used to store raw nanopore data – known as FAST5 – that prevents efficient analysis on high-performance computing (HPC) systems. To overcome this we have developed SLOW5, an alternative file format that permits efficient parallelisation and, thereby, acceleration of nanopore data analysis. For example, we show that using SLOW5 format, instead of FAST5, reduces the time and cost of genome-wide DNA methylation profiling by an order of magnitude on common HPC systems, and delivers consistent improvements on a wide range of different architectures. With a simple, accessible file structure and a ~25% reduction in size compared to FAST5, SLOW5 format will deliver substantial benefits to all areas of the nanopore community.

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